From: Gavin Sinclair <gsinclair@...>
Date: 2003-03-26T09:58:11+09:00
Subject: Re: [Q] changing a stream of 'print' method to a string

On Wednesday, March 26, 2003, 11:45:21 AM, makotz wrote:

> I have a question.
> How to change a stream of 'print' to a string? Is it able?

> Background:
> I want to test my program which print data to standard output.
> And I have no good idea to test output data.

>     ----------------------------------------
>     ##
>     ## main.rb
>     ##
>     def print_list(list)
>       list.each_with_index do |item, index|
>         print "#{index+1}: #{item}\n"
>       end
>     end
>     ----------------------------------------


  def print_list(list, out=STDOUT)
    list.each_with_index do |item, index|
      out.print "#{index+1}: #{item}\n"
    end
  end

In your test case:

  require 'stringio'

  buf = ""
  StringIO.open(buf, 'w') do |io|
    print_list(list, io)
  end

  assert_equal(expected_result, buf)

  
I think I got that right.

Gavin